The present invention relates to a fluorene derivative having both of a polymerizing property and liquid crystallinity, a composition thereof and a polymer thereof. They can be used for a retardation film, a polarizer, a liquid crystal aligning film, a anti-reflection film and a viewing angle compensation film which are structural elements for a liquid crystal display device.
Document 1: Japanese Patent Application Laid-Open No. 3111/1996
Document 2: Japanese Patent Application Laid-Open No. 17910/1995
Document 3: Japanese Patent Application Laid-Open No. 316032/1997
It is described in the document 1 that when a liquid crystal compound showing a polymerizing property is photopolymerized in the state that it is aligned, a state uniformly aligned is fixed and a polymer showing an optical anisotropy is obtained. Examples in which acrylate compounds were used as a liquid crystal compound showing a polymerizing property are described in the document 2 and the document 3. A high reactivity of the acrylate compounds and a transparency of the polymers are considered in these documents. Preferred examples of a polymerizable liquid crystalline acrylate compound are compounds (a) to (c) which are constituted by a cyclohexane ring and a benzene ring: 
However, an optically anisotropic film prepared using a polymer of a publicly known acrylate compound did not have satisfactory characteristics in heat resistance and mechanical properties such as surface hardness.
A subject of the present invention is to solve the problems in prior art, and a novel liquid crystalline compound is provided for this purpose. That is, a first object of the present invention is to provide a polymerizable liquid crystalline compound which satisfies a large part of properties such as a broad temperature range of a liquid crystal phase, a high clearing point, a large optical anisotropy, a low viscosity, a high compatibility with the other liquid crystalline compounds, an excellent aligning property, a high photopolymerizing property and a high solubility in an organic solvent. A second object of the present invention is to provide a polymer which is prepared from this compound and which satisfies a large part of properties such as a heat resistance, a surface hardness, a large optical anisotropy, a low water permeability (a high hygroscopic dimensional stability), a high gas barrier property, an optimum heat contraction (an optimum thermal expansion coefficient), a small haze value, a high transparency, a suitable refractive index, a high solvent resistance, a high weatherability, a high glass transition point, a large light transmittance (a low light loss), a high wettability and an optimum thermoelasticity.
The present invention is constituted by the following items.
[1] A fluorene derivative represented by Formula (1): 
wherein A1, A2 and A3 are independently a group represented by Formula (2), 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, pyridine-2,5-diyl, pyridazine-3,6-diyl, pyrimidine-2,5-diyl, dioxane-2,5-diyl, 1,4-cyclohexylene in which optional hydrogens are replaced by fluorines, or 1,4-phenylene in which optional hydrogens are replaced by fluorine and/or chlorine, and at least one of A1, A2 and A3 is the group represented by Formula (2); m, n and p are independently 0 or 1, and the total thereof is 1 to 3; R1 is xe2x80x94CN, xe2x80x94CF3, xe2x80x94CF2H, xe2x80x94CFH2, xe2x80x94OCF3, xe2x80x94OCF2H, xe2x80x94Nxe2x95x90Cxe2x95x90O, xe2x80x94Nxe2x95x90Cxe2x95x90S, xe2x80x94F, xe2x80x94Cl or alkyl having 1 to 20 carbon atoms, and in this alkyl, one hydrogen may be replaced by (meth)acryloyloxy or vinyloxy and optional xe2x80x94CH2xe2x80x94 may be replaced by xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94CF2xe2x80x94, xe2x80x94CHxe2x95x90CHxe2x80x94, xe2x80x94COOxe2x80x94, xe2x80x94OCOxe2x80x94 or xe2x80x94COxe2x80x94; R2 is hydrogen or methyl; Z1, Z2 and Z3 are independently a single bond, xe2x80x94Oxe2x80x94, xe2x80x94COOxe2x80x94, xe2x80x94OCOxe2x80x94, xe2x80x94CF2Oxe2x80x94, xe2x80x94OCF2xe2x80x94, xe2x80x94CH2Oxe2x80x94, xe2x80x94OCH2xe2x80x94, xe2x80x94CH2CH2xe2x80x94, xe2x80x94(CH2)4xe2x80x94, xe2x80x94CHxe2x95x90CHxe2x80x94, xe2x80x94CFxe2x95x90CFxe2x80x94 or xe2x80x94Cxe2x89xa1Cxe2x80x94; q is an integer of 0 to 10; and r is 0 or 1: 
wherein two X1""s are independently hydrogen, fluorine or alkyl having 1 to 8 carbon atoms.
[2] The fluorene derivative as described in the item [1], wherein both of two X1""s in Formula (2) are hydrogens.
[3] The fluorene derivative as described in the item [1], wherein both of two X1""s in Formula (2) are fluorines.
[4] The fluorene derivative as described in the item [1], wherein R2 in Formula (1) is hydrogen.
[5] The fluorene derivative as described in the item [1], wherein R2 in Formula (1) is methyl.
[6] The fluorene derivative as described in the item [1], wherein in Formula (1), R1 is alkyl or alkoxy, and R2 is hydrogen.
[7] The fluorene derivative as described in the item [1], wherein in Formula (1), R1 is alkyl or alkoxy, and R2 is methyl.
[8] The fluorene derivative as described in the item [1], wherein in Formula (1), R1 is alkyl or alkoxy; R2 is hydrogen; and both of two X1""s in Formula (2) are hydrogens.
[9] The fluorene derivative as described in the item [1], wherein in Formula (1), R1 is alkyl or alkoxy; R2 is methyl; and both of two X1""s in Formula (2) are fluorines.
[10] The fluorene derivative as described in the item [1], wherein in Formula (2), at least one X1 is methyl.
[11] The fluorene derivative as described in the item [1], wherein in A1, A2 and A3 in Formula (1), one of them is the group represented by Formula (2), and the other groups are independently 1,4-cyclohexylene, 1,4-phenylene, 1,4-cyclohexylene in which optional hydrogens are replaced by fluorines, or 1,4-phenylene in which optional hydrogens are replaced by fluorine and/or chlorine.
[12] The fluorene derivative as described in the item [1], wherein R1 is a group having (meth)acryloyloxy or vinyloxy.
[13] The fluorene derivative as described in the item [1], wherein in A1, A2 and A3 in Formula (1), one of them is the group represented by Formula (2), and the other groups are independently 1,4-cyclohexylene, 1,4-phenylene, 1,4-cyclohexylene in which optional hydrogens are replaced by fluorines, or 1,4-phenylene in which optional hydrogens are replaced by fluorine and/or chlorine; and R1 is a group having (meth)acryloyloxy or vinyloxy.
[14] The fluorene derivative as described in the item [1], wherein in Formula (1), A2 is the group represented by Formula (2); A1 and A3 are independently 1,4-cyclohexylene, 1,4-phenylene, 1,4-cyclohexylene in which optional hydrogens are replaced by fluorines, or 1,4-phenylene in which optional hydrogens are replaced by fluorine and/or chlorine; R1 is a group represented by Formula (LT); Z3 is xe2x80x94Oxe2x80x94; and q is an integer of 2 to 10: 
wherein R3 is hydrogen or methyl; r1 is 0 or 1; and q1 is an integer of 2 to 10.
[15] The fluorene derivative as described in the item [1], wherein in Formula (1), A2 is the group represented by Formula (2); A1 and A3 are independently 1,4-cyclohexylene, 1,4-phenylene or 1,4-phenylene in which optional hydrogens are replaced by fluorines; R1 is a group represented by Formula (LT-1); R2 is hydrogen; Z1 and Z2 are independently a single bond, xe2x80x94CH2CH2xe2x80x94, xe2x80x94COOxe2x80x94 or xe2x80x94OCOxe2x80x94; Z3 is xe2x80x94Oxe2x80x94; r is 1; and q is an integer of 2 to 10: 
wherein q1 is an integer of 2 to 10.
[16] The fluorene derivative as described in the item [1], wherein in Formula (1), A2 is the group represented by Formula (2); A1 and A3 are independently 1,4-cyclohexylene, 1,4-phenylene or 1,4-phenylene in which optional hydrogens are replaced by fluorines; R1 is a group represented by Formula (LT-2); R2 is hydrogen; Z1 and Z2 are independently a single bond, xe2x80x94CH2CH2xe2x80x94, xe2x80x94COOxe2x80x94 or xe2x80x94OCOxe2x80x94; Z3 is xe2x80x94Oxe2x80x94; r is 0; and q is an integer of 2 to 10: 
wherein q1 is an integer of 2 to 10.
[17] The fluorene derivative as described in the item [15] or [16], wherein in Formula (1) described in the item [1], both of Z1 and Z2 are single bonds; and in Formula (2) described in the item [1], two X1""s are independently hydrogen or methyl.
[18] The fluorene derivative as described in the item [15] or [16], wherein in Formula (1) described in the item [1], both of Z1 and Z2 are xe2x80x94CH2CH21; in Formula (2) described in the item [1], two X1""s are independently hydrogen or methyl.
[19] The fluorene derivative as described in the item [15] or [16], wherein in Formula (1) described in the item [1], Z1 is xe2x80x94COOxe2x80x94, and Z2 is xe2x80x94OCOxe2x80x94; and in Formula (2) described in the item [1], two X1""s are independently hydrogen or methyl.
[20] A liquid crystal composition comprising at least one of the fluorene derivatives as described in the item [1] and at least one of the other liquid crystalline compounds.
[21] A liquid crystal composition comprising at least one of the fluorene derivatives as described in the item [13] and at least one of the other liquid crystalline compounds.
[22] A polymerizable composition comprising at least one of the fluorene derivatives as described in the item [1] and at least one of the other monomers.
[23] A polymerizable composition comprising at least one of the fluorene derivatives as described in the item [13] and at least one of the other monomers.
[24] A polymer comprising a structural unit represented by Formula (3): 
wherein A1, A2, A3, m, n, p, R1, R2, Z1, Z2, Z3, q and r have the same definitions as those of the symbols in Formula (1) described in the item [1].
[25] The polymer as described in the item [24], obtained from the polymerizable composition described in the item [23].
[26] An optically anisotropic film obtained using the polymer as described in the item [24].
[27] An aligning film obtained using the polymer as described in the item [24].
[28] A anti-reflection film obtained using the polymer as described in the item [24].
[29] A retardation film obtained using the polymer as described in the item [24].
[30] A viewing angle compensation film obtained using the polymer as described in the item [24].
[31] A polarizer obtained using the polymer as described in the item [24].
[32] A liquid crystal display device comprising the polymer as described in the item [24].
[33] A liquid crystal display device comprising the polymer as described in the item [25].
[34] A liquid crystal display device comprising at least one of the liquid crystal composition described in the item [21], the optically anisotropic film described in the item [26], the aligning film described in the item [27], the reflection reducing film described in the item [28], the retardation film as described in the item [29], the viewing angle compensation film as described in the item [30] and the polarizer as described in the item [31].
First of all, the terms used in the present invention shall be explained. The meaning of the term xe2x80x98liquid crystallinexe2x80x99 in the present invention is not restricted only to having a liquid crystal phase. It is included in the meaning of the liquid crystalline that the compound itself does not have a liquid crystal phase but have such characteristics that it can be used as a component for a liquid crystal composition when it is mixed with the other liquid crystal compounds. The term xe2x80x98optionalxe2x80x99 shows that not only the position but also the number is optional. However, it does not include the case where the number is 0. Both of alkyl and alkoxy may be either a straight or a branched group. The same shall apply when optional xe2x80x94CH2xe2x80x94 is replaced by xe2x80x940xe2x80x94 or xe2x80x94CHxe2x95x90CHxe2x80x94 in these groups. (Meth)acryloyloxy means acryloyloxy or methacryloyloxy. (Meth)acrylate means acrylate or methacrylate. (Meth)acrylic acid means acrylic acid or methacrylic acid. 1,4-Cyclohexylene and dioxane-2,5-diyl may be either a trans form or a cis form unless otherwise described. The compound represented by Formula (1) may be shown as the compound (1). The same shall apply to the compounds represented by the other formulas.
The compound of the present invention is represented by Formula (1). The first characteristic of the compound (1) is to have a fluorene skeleton in a chemical structure thereof. A polymer obtained using the compound (1) shows very high characteristics in a mechanical strength and a heat resistance by having a fluorene skeleton. The second characteristic of the compound (1) is to show a high liquid crystallinity. The fluorene skeleton is considered to contribute to that the compound (1) has a wide temperature range of a liquid crystal phase and a suitable compatibility with the other liquid crystalline compounds. 
In Formula (1), at least one of A1, A2 and A3 is a fluorene group represented by Formula (2); and m, n and p are independently 0 or 1, and the total thereof is 1 to 3. 
Two X1""s in Formula (2) are independently hydrogen, fluorine or alkyl having 1 to 8 carbon atoms.
Accordingly, the compound (1) is, to be more specific, shown by Formula (1-1) to Formula (1-6): 
In these formulas, A1 to A3, R1, R2, Z1 to Z3, q and r have the same definitions as those of these symbols in Formula (1), and X1 has the same definition as that of X1 in Formula (2).
A1, A2 and A3 in Formula (1) are independently, when they are not the groups represented by Formula (2), 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, pyridine-2,5-diyl, pyridazine-3,6-diyl, pyrimidine-2,5-diyl, dioxane-2,5-diyl, 1,4-cyclohexylene in which optional hydrogens are replaced by fluorines, or 1,4-phenylene in which optional hydrogens replaced by fluorine and/or chlorine. The preferred configuration for 1,4-cyclohexylene and dioxane-2,5-diyl is trans.
The preferred examples of A1, A2 or A3 other than the fluorene group are 1,4-cyclohexylene, 2,2-difluoro-1,4-cyclohexylene, 3,3-difluoro-1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1,4-phenylene, 2,3-difluoro-1,4-phenylene, 3,5-difluoro-1,4-phenylene, pyridine-2,5-diyl, pyridazine-3,6-diyl and pyrimidine-2,5-diyl. Among them, the more preferred examples thereof are 1,4-cyclohexylene, 2,2-difluoro-1,4-cyclohexylene, 3,3-difluoro-1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1,4-phenylene, 2,3-difluoro-1,4-phenylene, and 3,5-difluoro-1,4-phenylene.
R2 in Formula (1) is hydrogen or methyl, and r is 0 or 1. That is, an end group at a right side of Formula (1) is vinyloxy or isopropenyloxy when r is 0, and it is acryloyloxy or methacryloyoxy when r is 1. Considering the polymerization reactivity, R2 is preferably hydrogen.
Z1, Z2 and Z3 in Formula (1) are independently a single bond, xe2x80x94Oxe2x80x94, xe2x80x94COOxe2x80x94, xe2x80x94OCOxe2x80x94, xe2x80x94CF2Oxe2x80x94, xe2x80x94OCF2xe2x80x94, xe2x80x94CH2Oxe2x80x94, xe2x80x94OCH2xe2x80x94, xe2x80x94CH2CH2xe2x80x94, xe2x80x94(CH2)4xe2x80x94, xe2x80x94CHxe2x95x90CHxe2x80x94, xe2x80x94CFxe2x95x90CFxe2x80x94 or xe2x80x94Cxe2x89xa1Cxe2x80x94. When Z1, Z2 or Z3 is xe2x80x94COOxe2x80x94, xe2x80x94OCOxe2x80x94, xe2x80x94CF2Oxe2x80x94, xe2x80x94OCF2xe2x80x94, xe2x80x94CHxe2x95x90CHxe2x80x94 or xe2x80x94Cxe2x89xa1Cxe2x80x94, the compound (1) shows a liquid crystal phase in a wide temperature range. When Z1, Z2 or Z3 is xe2x80x94CF2Oxe2x80x94 or xe2x80x94OCF2xe2x80x94, the compound (1) has a relatively small viscosity. In Formula (1), q is an integer of 0 to 10. When q is 0, Z1, Z2 or Z3 connected to an end group (RT) in Formula (1) is a single bond: 
R1 in Formula (1) is xe2x80x94CN, xe2x80x94CF3, xe2x80x94CF2H, xe2x80x94CFH2, xe2x80x94OCF3, xe2x80x94OCF2H, xe2x80x94Nxe2x95x90Cxe2x95x90O, xe2x80x94Nxe2x95x90Cxe2x95x90S, xe2x80x94F, xe2x80x94Cl or alkyl having 1 to 20 carbon atoms. In this alkyl, one hydrogen may be replaced by (meth)acryloyloxy or vinyloxy, and optional xe2x80x94CH2xe2x80x94 may be replaced by xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94CF2xe2x80x94, xe2x80x94CHxe2x95x90CHxe2x80x94, xe2x80x94COOxe2x80x94, xe2x80x94OCOxe2x80x94 or xe2x80x94COxe2x80x94. However, not preferred is a group in which a plurality of continuous xe2x80x94CH2xe2x80x94 is replaced by xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94COOxe2x80x94, xe2x80x94OCOxe2x80x94 or xe2x80x94COxe2x80x94. The preferred examples of R1 are xe2x80x94CN, xe2x80x94CF3, xe2x80x94CF2H, xe2x80x94CFH2, xe2x80x94OCF3, xe2x80x94OCF2H, straight alkyl having 1 to 10 carbon atoms, straight alkoxy having 1 to 10 carbon atoms, straight alkoxyalkyl having 2 to 10 carbon atoms, and these alkyl, alkoxy and alkoxyalkyl groups in which one hydrogen is replaced by (meth)acryloyloxy or vinyloxy. The example of the group in which one hydrogen is replaced by (meth)acryloyloxy or vinyloxy is a group represented by Formula (LT): 
wherein R3 is hydrogen or methyl; r1 is 0 or 1; and q1 is an integer of 2 to 10.
The more preferred specific examples of R1 are xe2x80x94CN, xe2x80x94CF3, xe2x80x94CF2H, xe2x80x94CFH2, xe2x80x94OCF3, xe2x80x94OCF2H, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, methoxy, ethoxy, propyloxy, butyloxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy, methoxymethyl, methoxyethyl, a group represented by (LT-1) and a group represented by (LT-2). Among them, the particularly preferred groups are alkyl, alkoxy, the group represented by (LT-1) and the group represented by (LT-2). 
wherein q1 is an integer of 2 to 10.
The preferred example of the compound in which R1 is the group represented by Formula (LT) is a compound represented by the following formula: 
wherein A1 and A3 are independently 1,4-cyclohexylene, 1,4-phenylene, 1,4-cyclohexylene in which optional hydrogens are replaced by fluorines, or 1,4-phenylene in which optional hydrogens are replaced by fluorine and/or chlorine; R2 and R3 are independently hydrogen or methyl; Z1 and Z2 are independently a single bond, xe2x80x94Oxe2x80x94, xe2x80x94COOxe2x80x94, xe2x80x94OCOxe2x80x94, xe2x80x94CF2Oxe2x80x94, xe2x80x94OCF2xe2x80x94, xe2x80x94CH2Oxe2x80x94, xe2x80x94OCH2xe2x80x94, xe2x80x94CH2CH2xe2x80x94, xe2x80x94(CH2)4xe2x80x94, xe2x80x94CHxe2x95x90CHxe2x80x94, xe2x80x94CFxe2x95x90CFxe2x80x94 or xe2x80x94Cxe2x89xa1Cxe2x80x94; q and q1 are independently an integer of 2 to 10; r and r1 are independently 0 or 1; and two X1""s are independently hydrogen or methyl.
The preferred examples of the compound in which R1 is the group represented by Formula (LT-1) and the preferred examples of the compound in which R1 is the group represented by Formula (LT-2) shall be shown below: 
In these formulas, A1 and A3 are independently 1,4-cyclohexylene, 1,4-phenylene or 1,4-phenylene in which optional hydrogens are replaced by fluorines; q and q1 are independently an integer of 2 to 10; and two X1""s are independently hydrogen or methyl.
Next, a production process for the fluorene derivative represented by Formula (1) shall be explained. The compound (1) can easily be produced by suitably combining publicly known reaction processes described in Houben-Wyle, Methods of Organic Chemistry (George Thieme Verlag, Stuttgart), Organic Syntheseses (John Wily and Sons, Inc.), Organic Reactions (John Wily and Sons, Inc.), Comprehensive Organic Synthesis (Pergamon Press), and New Experimental Chemistry Course (Maruzen). In this case, commercial products can be used for 2-bromofluorene, 2,7-dibromofluorene, 2-bromo-7-pentylfluorene and 2-amino-7-bromofluorene. Also, the production processes of 2-bromo-7-hydroxyfluorene and 7-bromofluorene-2-carboxylic acid are reported (Mol. Cryst. Liq. Cryst., 1987, 150B, 361-73). The production processes in which these compounds are used as raw materials shall specifically be explained.
A fluorene derivative in which in Formula (1), A1 is fluorene-2,7-diyl, Z1 is a single bond, and r is 1 can be synthesized by Scheme 1: 
A substituent R1 such as alkyl is introduced into 2-amino-7-bromofluorene (4) to obtain 2-substituted-7-aminofluorene (5). The compound (5) is turned into a diazonium salt, and then halogen such as bromine is reacted therewith, whereby 2-substituted-7-bromofluorene (6) is obtained. A compound (8) is obtained by a cross-coupling reaction of the compound (6) with a bromide (7). A protective group for a hydroxyl group may be one usually used in organic synthetic chemistry such as tetrahydropyranyloxy (THP), but a protective group which is optimum for the conditions of the cross-coupling reaction has to be selected. A compound (9) is obtained by removing the protective group from the compound (8) under an acidic condition. The compound (9) is subjected to dehydration condensation with various acrylic acid compounds to thereby obtain a compound (1-11). In the dehydration condensation reaction, a condensing agent such as dicyclohexylcarbodiimide (DCC) can be used. When an acid chloride of an acrylic acid compound is available, the compound (9) may be esterified by reacting with the acid chloride under a basic condition.
A fluorene derivative in which in Formula (1), A1 is fluorene-2,7-diyl, Z1 is xe2x80x94COOxe2x80x94, and r is 1 can be synthesized by Scheme 2: 
A substituent R1 is introduced into ethyl 7-bromofluorene-2-carboxylate (10) by the method described in above Scheme 1. The resulting compound (11) is hydrolyzed under a basic condition to thereby obtain a corresponding compound (12). The compound (12) is subjected to dehydration condensation with a compound (13) using the method described in Scheme 1, whereby a compound (14) is obtained. A compound (15) is obtained by removing a protective group for the compound (14). The compound (15) is derived into a compound (1-12) by reacting with an acrylic acid compound.
A fluorene derivative in which in Formula (1), A1 is fluorene-2,7-diyl, Z1 is xe2x80x94OCOxe2x80x94, and r is 1 can be synthesized by Scheme 3: 
A substituent R1 is introduced into a bromide (16) by the method described above and then reacted with a compound (18) to prepare a compound (19). A protective group for the compound (19) is removed to obtain a compound (20), and then this is subjected to dehydration condensation with an acrylic acid compound, whereby a compound (1-13) is obtained. A fluorene derivative having a hydroxyl group such as a compound (17) can be produced as well by acetylating fluorene by a Friedel-Crafts reaction, then carrying out a Baeyerxe2x80xa2Villiger reaction with a peroxide and finally carrying out hydrolysis. One example of this method shall be explained in Example 1 described later.
A fluorene derivative in which in Formula (1), A1 is fluorene-2,7-diyl, Z1 is xe2x80x94CF2Oxe2x80x94, and r is 1 can be synthesized by Scheme 4: 
The carboxylic acid (12) described above is reacted with 1,3-propanedithiol and trifluoromethanesulfonic acid according to a method of a literature (Angew. Chem. Int. Engl., 2001, 40 (8), 1480), whereby an intermediate (21) which is stable at a room temperature is obtained. This is reacted with the compound (13) under a basic condition, and the resulting dithiane compound is reacted with a nucleophilic fluorinating agent such as DAST ((diethylamino)sulfur trifluoride) or an HF/triethylamine complex, whereby a compound (22) is obtained. A protective group for this compound is removed to prepare a compound (23), and then this compound is subjected to dehydration condensation with an acrylic acid compound, whereby a compound (1-14) is obtained.
A fluorene derivative in which in Formula (1), A1 is fluorene-2,7-diyl, Z1 is xe2x80x94OCF2xe2x80x94, and r is 1 can be synthesized by Scheme 5: 
The compound (17) described above is reacted with a compound (24) under a basic condition to prepare a compound (25). A protective group for the compound (25) is removed under an acidic condition, and the resulting compound (26) is reacted with an acrylic acid compound, whereby a compound (1-15) is obtained.
A fluorene derivative in which in Formula (1), A1 is fluorene-2,7-diyl, Z1 is xe2x80x94CH2Oxe2x80x94, and r is 1 can be synthesized by Scheme 6: 
The compound (11) described above is derived into a compound (27) by a reducing agent such as lithium aluminum hydride. A hydroxyl group of the compound (27) is halogenated with a halogenating agent. If hydrogen bromide is used as the halogenating agent, a compound (28) is obtained. The compound (28) is reacted with the compound (13) under a basic condition to prepare a compound (29). The compound (29) is derived into a compound (1-16) by removing a protective group and then subjecting to dehydration condensation with an acrylic acid compound.
A fluorene derivative in which in Formula (1), A1 is fluorene-2,7-diyl, Z1 is xe2x80x94OCH2xe2x80x94, and r is 1 can be synthesized by Scheme 7: 
The compound (17) described above is reacted with a compound (31) under a basic condition to prepare a compound (32). A protective group is removed from the compound (32) under an acidic condition, and then the resulting compound (33) is subjected to dehydration condensation with an acrylic acid compound, whereby a compound (1-17) is obtained.
A fluorene derivative in which in Formula (1), A1 is fluorene-2,7-diyl, Z1 is xe2x80x94CHxe2x95x90CHxe2x80x94, and r is 1 can be synthesized by Scheme 8: 
The compound (11) described above is reduced by a reducing agent such as DIBAL (diisobutylaluminum hydride) to obtain a compound (34). The compound (34) is reacted with a compound (35) to obtain a compound (36). A protective group of the compound (36) is removed under an acidic condition to obtain an alcohol (37). The compound (37) is subjected to dehydration condensation with an acrylic acid compound, whereby a compound (1-18) is obtained.
A fluorene derivative in which in Formula (1), A1 is fluorene-2,7-diyl, Z1 is xe2x80x94CFxe2x95x90CFxe2x80x94, and r is 1 can be synthesized by Scheme 9: 
The bromide (6) described above is treated with n-BuLi to prepare a corresponding lithium compound, and then it is reacted with tetrafluoroethylene to obtain a compound (38). The compound (7) is treated with n-BuLi to prepare a corresponding lithium compound, and then it is reacted with the compound (38) to obtain a compound (39). A protective group of the compound (39) is removed under an acidic condition to prepare a compound (40). The compound (40) is subjected to dehydration condensation with an acrylic acid compound, whereby a compound (1-19) is obtained.
A fluorene derivative in which in Formula (1), A1 is fluorene-2,7-diyl and Z1 is xe2x80x94Cxe2x89xa1Cxe2x80x94 and in which r is 1 can be synthesized by Scheme 10: 
The compound (34), the synthetic method of which has been shown previously, is reacted with triphenylphosphine and carbon tetrabromide to obtain a compound (41). The compound (41) is treated with a base such as n-BuLi to thereby obtain a compound (42). The compound (42) is subjected to cross-coupling with the compound (7) making use of, for example, a Castro reaction or a Sonogashira reaction to thereby obtain a compound (43). A protective group of the compound (43) is removed under an acidic condition, and then the resulting compound (44) is subjected to dehydration condensation with an acrylic acid compound, whereby a compound (1-20) is obtained. A linkage group xe2x80x94Cxe2x89xa1Cxe2x80x94 can be introduced as well into a fluorene ring by subjecting a corresponding fluorene bromide product to a coupling reaction with acetylene in which one hydrogen atom is protected with TMS (trimethylsilyl) and then removing the protective group.
A fluorene derivative in which X1 in Formula (2) is fluorine and r in Formula (1) is 1 can be synthesized by Scheme 11: 
A compound (45) is oxidized by oxygen under a base condition to thereby obtain a compound (46). The compound (46) is derived into a compound (47) by reacting with ethanedithiol. The compound (47) is fluorinated with a nucleophilic fluorinating agent to thereby obtain a compound (48). A protective group of the compound (48) is removed under an acidic condition, and then the resulting compound (49) is subjected to dehydration condensation with an acrylic acid compound, whereby a compound (1-21) is obtained. A fluorene derivative in which X1 in Formula (2) is alkyl is obtained by reacting the compound (46) with two equivalents of alkyl halide.
A fluorene derivative in which both of X1""s in Formula (2) are methyl can be synthesized by Scheme 12: 
A compound (50) can be produced by reacting the fluorenone derivative (46) described above with two or more equivalents of methyl iodide in the presence of a base, particularly a radical anion. When the reaction is slow, irradiation with a ultrasonic field is effective. This production process can be referred to a literature (Tetrahedron Lett., 1990, 31 (43), 6155). Methyl can be introduced at any stage. For example, the compound (1) can be produced as well by introducing methyl into commercially available fluorenone on the conditions described above, and then modifying 2- and 7-positions of the fluorene ring. The compound (1) in which X1 in Formula (2) is alkyl having 2 or more carbon atoms can be produced by using alkyl iodide having 2 or more carbon atoms in place of methyl iodide.
A fluorene derivative in which one of X1""s in Formula (2) is methyl and the other is hydrogen can be synthesized by Scheme 13: 
A compound (51) can be produced by reacting the fluorene derivative (45) described above with a base and then methyl iodide. A hydrogen atom at a 9-position of fluorene has a high acidity and is readily subjected to deprotonation with a base such as n-butyllithium, and therefore methyl can be introduced thereinto at any stage. For example, the compound (1) can be produced as well by introducing methyl into commercially available fluorene on the conditions described above and then modifying 2- and 7-positions of the fluorene ring. The compound (1) in which X1 is alkyl having 2 or more carbon atoms can be produced by using alkyl iodide having 2 or more carbon atoms in place of methyl iodide. In this process, a fluorene derivative in which both of X1""s are alkyls can be derived by using two equivalents of n-butyllithium.
A fluorene derivative in which r in Formula (1) is 0 is vinyl ether. A compound (1-22) can be produced by reacting a compound (52) with vinyl ether in the presence of a metal catalyst. 
A fluorene derivative in which in Formula (1), A2 is fluorene-2,7-diyl can be synthesized by Scheme 15: 
A compound (54) having a ring A1 is obtained by using a commercial fluorene derivative (53) (a compound in which Y is Br, OH or COOH) and applying the processes described in Schemes 1 to 10. F can be introduced into a 9-position of a fluorene ring in the compound (54) by applying the process described in Scheme 11. A compound (55) is obtained by introducing an amino group, an ethoxycarbonyl group, a hydroxyl group or a hydrocarbonyl group into a 7-position of a fluorene ring in the compound (54). An amino group, an ethoxycarbonyl group, a hydroxyl group and a hydrocarbonyl group can be introduced by publicly known conventional methods. For example, an amino group can be introduced by nitration with fuming nitric acid and reduction reaction subsequent thereto. An ethoxycarbonyl group can be introduced by carrying out in order acetylation by a Friedel-Crafts reaction, oxidation by sodium hypochlorite and esterification. A hydroxyl group can be introduced by reduction of an amino group to diazonium with sodium nitrite and hydrolysis by sulfuric acid subsequent thereto. A hydrocarbonyl group can be introduced by the reduction of an ethoxycarbonyl group with diisobutylaluminum hydride. The resulting compound (55) can be derived into the compound (1) by applying the processes described in schemes 1 to 14. The compound (1) in which A3 is a fluorene ring can be synthesized as well by applying the processes described in Schemes 1 to 14.
Among the fluorene derivatives obtained by these production processes, the examples of the compound showing particularly preferred characteristics shall specifically be shown. In the following examples, 1,4-cyclohexylene is preferably a trans form. 
The compound (1) shows high characteristics as liquid crystal such as a wide temperature range of a liquid crystal phase and a suitable compatibility with the other liquid crystalline compounds. Accordingly, at least one of the compounds (1) which is combined with the other liquid crystalline compounds can be used as it is for a display device as a liquid crystalline composition. In this case, polymerizable compounds can be used as the other liquid crystalline compounds. The compound (1) is useful for improving a birefringence factor of a liquid crystal composition and a compatibility at a low temperature. Also, this composition can be polymerized according to the purposes. Another composition of the present invention is a polymerizable composition comprising at least one of the compounds (1) and the other monomers. The polymerizable composition preferably shows a liquid crystal phase but may not show a liquid crystal phase depending on the purposes. Explanation regarding this polymerizable composition is included in subsequent explanation regarding the polymer.
The polymer of the present invention is a polymer comprising at least one kind of the structural units represented by Formula (3): 
The structural unit represented by Formula (3) has a chemical structure in which a double bond at an end of the compound (1) is opened. Accordingly, the symbols in Formula (3) mean just the same as those in Formula (1). R2 in Formula (3) is preferably hydrogen rather than methyl from the viewpoint of easiness in polymerization.
The example of the structural unit in which R1 is a group having (meth)acryloyloxy or vinyloxy is a structural unit represented by Formula (3-1): 
wherein A1 to A3, m, n, p, R2, Z1, Z2 and r mean the same as those in Formula (1); q and q1 are independently an integer of 2 to 10; R3 is hydrogen or methyl; and r1 is 0 or 1.
A homopolymer can be prepared from the compound (1) by homopolymerization. Also, a plurality of different kinds of the compounds (1) can be used for copolymerization. Further, a copolymer may be prepared by polymerizing a polymerizable composition comprising at least one of the compounds (1) and the other monomers. The other monomers shall not specifically be restricted as long as they do not reduce the film-forming property and the mechanical strength and can be copolymerized with the compound (1). The other monomers may or may not show a liquid crystallinity.
The examples of the other monomers showing no liquid crystallinity are vinyl esters, aromatic vinyl compounds, xcex1-substituted styrene compounds, halogen nucleus-substituted styrenes, vinyl ethers, alkyl vinyl ketones, (meth)acrylates, olefins, dienes, alkyl itaconates, N-vinylacetamide and xcex1,xcex2-vinylnaphthalene. The specific examples of the vinyl esters are vinyl acetate, vinyl pivalate, vinyl 2,2-dimethylbutanoate, vinyl 2,2-dimethylpentanoate, vinyl 2-methyl-2-butanoate, vinyl propionate, vinyl stearate and vinyl 2-ethyl-2-methylbutanoate. The specific examples of the aromatic vinyl compounds are vinyl p-tert-butylbenzoate, vinyl N,N-dimethylaminobenzoate and vinyl benzoate. The specific examples of the xcex1-substituted styrene compounds are styrene, o-chloromethylstyrene, m-chloromethylstyrene, p-chloromethylstyrene, xcex1-methylstyrene and nucleus-substituted products thereof. The specific examples of the halogen nucleus-substituted styrenes are o-chlorostyrene, m-chlorostyrene and p-chlorostyrene. The specific examples of the vinyl ethers are ethyl vinyl ether, hydroxybutyl monovinyl ether, tert-amyl vinyl ether and cyclohexanedimethanolmethyl vinyl ether. The specific examples of the alkyl vinyl ketones are methyl vinyl ketone and isobutyl vinyl ketone. The specific examples of the (meth)acrylates are methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate and phenyl (meth)acrylate. The specific examples of the olefins are propene, vinyl chloride and vinyl fluoride. The specific examples of the dienes are butadiene and isoprene. The specific examples of the alkyl itaconates are dimethyl itaconate, diethyl itaconate, dibutyl itaconate and diisopropyl itaconate.
Among the other monomers, the specific examples of the compounds showing a liquid crystallinity are liquid crystalline acrylic acid derivatives such as the compounds (a) to (c) described above. The acrylic acid compounds are suited since they provide polymers which are transparent and have a high mechanical strength. The liquid crystalline acrylic acid derivatives can be used as well in order to control a temperature range of a liquid crystal phase of the polymerizable composition. The copolymer obtained from the polymerizable composition comprising at least one of the compounds (1) may be any of a random copolymer, an alternate copolymer, a block copolymer and a graft copolymer.
A polymer prepared by heat polymerization can be applied to various protective films and liquid crystal aligning films. In photopolymerization, polymerizable molecules can be polymerized in the state that they are arranged in a direction of polarized light by using polarized light, particularly polarized UV light. Accordingly, a polymer obtained by photopolymerization can be applied to aligning films requiring no rubbing, in addition to various protective films and liquid crystal aligning films. The polymer of the present invention has an optical anisotropy and therefore can be used alone as a retardation film or applied to a polarizer, a circular polarizer, an elliptic polarizer, a anti-reflection film, a color compensation plate and a viewing angle compensation plate by combining with the other retardation film.
The retardation film is obtained by applying a composition obtained by adding an optimum amount of an optically active compound to the compound (1) on a substrate subjected to aligning treatment and polymerizing it. The texture of the composition containing the compound (1) shows a helical structure by adding the optically active compound. This helical structure is fixed by polymerization of the compound (1), and a retardation film is formed. The characteristics of the retardation film depends on a pitch length of the resulting helical structure. This pitch length can be controlled by the kind and the addition amount of the optically active compound. This addition amount is usually 0.01 to 10% by weight, preferably 0.01 to 5% by weight. One optically active compound may be added. Plural optically active compounds may be added for the purpose of offsetting a temperature dependency of the pitch length. Further, a monomer other than the compound (1) may be contained in addition to this compound (1) and the optically active compound.
In order to produce the polymer of the present invention, a polymerizing method suited to the uses thereof is preferably selected. In producing an optically anisotropic film such as a retardation film and a polarizer, it is required to quickly carry out polymerization in the state that the liquid crystal state is maintained, and therefore preferred is a polymerizing method in which energy such as a UV ray or an electron beam is irradiated. In this case, the compound (1) is polymerized with the other monomer which is an optional component, in the presence of a photoradical polymerization initiator. The examples of the photoradical polymerization initiator are 2-hydroxy-2-methyl-1-phenylpropane-1-one, 1-hydroxycyclohexyl phenyl ketone, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1-one, benzyl dimethyl ketal and a mixture of 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropane-1,2,4-diethylxanthone and methyl p-dimethylaminobenzoate.
Heat polymerization is preferred for producing an aligning film, a anti-reflection film and a viewing angle compensation plate. In heat polymerization, the compound (1) is polymerized with the other monomer which is an optional component at a reaction temperature of 0 to 150xc2x0 C. for 1 to 100 hours in the presence of a radical polymerization initiator. The examples of the radical polymerization initiator are benzoyl peroxide, diisopropyl peroxydicarbonate, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxypivalate, t-butyl peroxydiisobutyrate, lauroyl peroxide, dimethyl 2,2xe2x80x2-azobisisobutyrate (MAIB), azobisisobutyronitrile (AIBN) and azobiscyclohexanecarbonitrile (CAN).
In this heat polymerization, a solvent can be used. The solvent may be one usually used in heat polymerization. The preferred solvents are benzene, toluene, xylene, hexane, heptane, octane, nonane, decane, tetrahydrofuran and N-methylpyrrolidone. It is not meaningful so much to restrict a use proportion of the solvent in polymerization. The reasons are that the required polymer concentration is different depending on the uses of the polymer and that this concentration can be controlled by dilution after the polymerization. A used proportion of the solvent in the polymerization may be decided by every individual case considering economical viewpoints such as a polymerization efficiency, a solvent cost and an energy cost. These solvents can be used as well in photopolymerization. In producing an aligning film, a anti-reflection film and a viewing angle compensation plate by photopolymerization, it is preferred to apply a solution obtained by dissolving the compound (1) or the polymerizable composition on a substrate by spin coating, and irradiate it with light after removing the solvent to polymerize it.